<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>过渡</title>
		<style type="text/css">
			.box{
				width: 100px;
				height: 400px;
				background-color: aqua;
				/* 过渡 
				ease:默认值：慢-快-慢
				ease-in：低速开始
				ease-out：低速结束
				ease-in-out：低速开始和低俗结束
				linear：均速
				*/
				transition: width 3s ease-in-out 2s;
				}
				/* 鼠标悬停 */
				.box:hover{
					width: 1200px;
					background-color: blueviolet;
				}
		</style>
	</head>
	<body>
		<div class="box"></div>
	</body>
</html>